Nevertheless—patiently, doggedly, slowly—the replicators would collate this data and broadcast it back to their point of origin: to us, or at least to our listening satellites.
Then, in its senescence as a complex machine, the replicator colony would break down into individual clusters of simple cells, identify another bright or nearby star, and use accumulated volatiles mined from the host cometary nucleus to propel its seeds out of the solar system. (They would leave behind a tiny fragment of themselves to act as a radio repeater, a passive node in a growing network.)
These second-generation seeds would drift in interstellar space for years, decades, millennia. Most would eventually perish, lost on fruitless trajectories or drawn into gravitational eddies. Some, unable to escape the faint but distant pull of the sun, would fall back into the solar Oort Cloud and repeat the process, stupidly but patiently eating ice and recording redundant information. If two strains encountered each other they would exchange cellular material, average out copying errors induced by time or radiation, and produce offspring nearly but not exactly like themselves.
Some few would reach the icy halo of a nearby star and begin the cycle anew, this time gathering fresh information, which they would eventually send home in bursts of data, brief digital orgasms. Binary star, they might say, no dark planetary bodies; or they might say, White dwarf star, one dark planetary body.
And the cycle would repeat again.
And again.
And again, one star to the next, stepwise, centuries by millennia, agonizingly slowly, but speedily enough as the galaxy measures time—as we clocked the external universe from our entombment. Our days would encompass their years by the hundreds of thousands and a decade of our slow time would see them infest most of the galaxy.
Information passed at light-speed node-to-node would be forwarded, would modify behavior, would direct new replicators toward unexplored territory, would suppress redundant information so that core nodes were not overwhelmed. In effect we would be wiring the galaxy for a kind of rudimentary thought. The replicators would build a neural network as big as the night sky, and it would talk to us.
Were mere risks? Of course there were risks.
Absent the Spin, Wun said, the Martians would never have approved such an arrogant appropriation of the galaxy's resources. This wasn't just an act of exploration; it was an intervention, an imperial reordering of the galactic ecology. If there were other sentient species out there—and the existence of the Hypothetical had pretty much answered that question in the affirmative—the dispersal of the replicators might be misunderstood as aggression. Which might invite retaliation.
The Martians had only reconsidered this risk when they detected Spin structures under construction above their own northern and southern poles.
"The Spin renders objections moot," Wun said, "or nearly so. With luck the replicators will tell us something important about the Hypotheticals, or at least the extent of their work in the galaxy. We might be able to discern the purpose of the Spin. Failing that, the replicators will serve as a sort of warning beacon to other intelligent species facing the same problem. Close analysis would suggest to a thoughtful observer the purpose for which the network was constructed. Other civilizations might choose to tap into it. The knowledge could help them protect themselves. To succeed where we failed."
"You think we'll fail?"
Wun shrugged. "Haven't we failed already? The sun is very old now. You know that, Tyler. Nothing lasts indefinitely. And under the circumstances, for us, even 'indefinitely' isn't a very long time."
Maybe it was the way he said it, smiling his sad little Martian sincerity-smile and leaning forward in his wicker chair, hit the weight of the pronouncement was quietly shocking.
Not that it surprised me. We all knew we were doomed. Doomed, at the very least, to live out our lives under a shell that was the only thing protecting us from a hostile solar system. The sunlight that had made Mars habitable would cook the Earth if the Spin membrane was stripped away. And even Mars (in its own dark envelope) was rapidly slipping out of the so-called habitable zone. The mortal star that was the mother of all life had passed into bloody senescence and would kill us without conscience.
Life had been born on the fringe of an unstable nuclear reaction. That was true and it had always been true; it had been true before the Spin, even when the sky was clear and summer nights twinkled with distant, irrelevant stars. It had been true but it hadn't mattered because human life was short; countless generations would live and die in the span of a solar heartbeat. But now, God help us, we were outliving the sun. Either we would end up as cinders circling its corpse or we would be preserved into eternal night, encapsulated novelties with no real home in the universe.
"Tyler? Are you all right?"
"Yes," I said. Thinking, for some reason, of Diane. "Maybe the best we can hope for is a little understanding before the curtain comes down."
"Curtain?"
"Before the end."
"It's not much consolation," Wun admitted. "But yes, it may be the best we can hope for."
"Your people have known about the Spin for millennia. And in all that time you haven't been able to learn anything about the Hypotheticals?"
"No. I'm sorry. I don't have that to offer. About the physical nature of the Spin we have only a few speculations." (Which Jason had recently attempted to explain to me: something about temporal quanta, mostly mathematics and far beyond the reach of practical engineering, Martian or terrestial.) "About the Hypotheticals themselves, nothing at all. As for what they want from us—" He shrugged. "Only more speculation. The question we asked ourselves was, what was special about the Earth when it was encapsulated? Why did the Hypotheticals wait to spin Mars, and what made them choose this particular moment in our history?"
"You have answers to that?"
One of his handlers knocked at the door and opened it. A balding guy in a tailored black suit. He spoke to Wun but he looked at me: "Just a reminder. We have the EU rep coming in. Five minutes." He held the door wide, expectantly. I stood up.
"Next time," Wun said.
"Soon, I hope."
"As soon as I can arrange it."
It was late and I was done for the day. I left through the north door. On my way to the parking lot I stopped at the wooden hoarding where the new addition to Perihelion was under construction. Between gaps in the security wall I could see a plain cinder-block building, huge external pressure tanks, pipes as thick as barrels plumbed through concrete embrasures. The ground was littered with yellow PTFE insulation and coiled copper tubing. A foreman in a white hard hat barked orders at men pushing wheelbarrows, men with safety goggles and steel-toed boots.
Men building an incubator for a new kind of life. This was where the replicators would be grown in cradles of liquid helium and prepped for their launch into the cold places of the universe: our heirs, in a sense, bound to live longer and travel farther than human beings ever would. Our final dialogue with the universe. Unless E.D. had his way and canceled the project entirely.
* * * * *
Molly and I took a beach walk that weekend.
It was a cloudless late-October Saturday. We had hiked a quarter mile of cigarette-stub-littered sand before the day got uncomfortably warm and the sun grew insistent, the ocean giving back the light in dazzling pinpoints, as if shoals of diamonds were swimming far offshore. Molly wore shorts and sandals and a white cotton T-shirt that had begun to stick to her body in alluring ways, a visor cap with the bill pulled down to shade her eyes.
"I never did understand this," she said, swiping her wrist across her forehead, turning back to face her own tracks in the sand.